Now is the time to get your initial numbers for percent out-of-bloom for cranberry fruitworm management. It is good to get 1-2 calculations in before you hit 50% oob, so you can be a bit more confident in your numbers. On June 23, we had BL at 19% oob, Dem and CQ at 17% at State Bog. Select 10 random uprights and record separately the number of fruit and flowers. Divide the number of fruit (pinheads, etc.) by the number of all flower stages. All varieties, except Howes, should be treated 0-7 days after 50% oob. See Page 33 in the 2021-23 Chart Book for more details.
If you are using traps to monitor and plan management for Spag and using growth regulators (Confirm Intrepid), or Altacor, spray 3 weeks after moth flight begins (us. Around late June); make at least 1 more application 10-14 days later. When treating with Delegate, apply 10-14 days after peak flight (mid-late July). For BHF, treated 2 weeks after the onset of flight and again 10 days later. Intrepid is the best choice. Conventional insecticides (e.g., Diazinon) cannot be used (illegal!) as they interfere with pollination. See pp 30-31 in the Chart Book for more information.
If you are trying to control Fairy Ring, Ferbam can be applied at 9 lb/100 gal water through July 31. Do not apply after July 31.You can only do one application of Ferbam. This goes out as a soil drench at a rate of 1 gal/sq ft. Treat 3 ft beyond the advancing ring and 2 feet within the line.
If you are using Stinger for control of asters or legume weeds (like wild bean), wait until after fruit set to apply. Vines are very sensitive to Stinger prior to bloom. Use the lowest effective rate. Spray only to wet the leaves, not to run-off. Minimize drift/contact of Stinger with cranberry vines. Recovery from Stinger injury can take several years.
In general, if you can avoid spraying herbicides during bloom, that is a good approach. However, sometimes to get the best results, you have to apply based on what the WEED is doing compared to what the VINES are doing. Select applications must wait until fruit set; IntensityOne and Poast have no timing restrictions during the bloom period. However, always be careful when using crop oil, especially when bloom is out and when the temperatures are high. IntensityOne uses an NIS whereas Poast uses a crop oil.
Clarification on the use of adjuvants with Proline. The use is recommended for some crops as a possible additive, and it’s recommended to use the lowest possible rate. However, there is no specific language that recommends adding an adjuvant for cranberries (listed as the “berry” group). On the other hand, the label does not prohibit the use. At this time, the take-home would be you do not have to add an adjuvant with Proline, but you can if you feel it improves the efficacy.
We are holding a 2-hr Zoom meeting on Wednesday, June 29th, 8-10 AM for 2 contact hours. Please contact Robyn for the link.
